KOA2 Jailbreak consistent, KUAL not found

KOA2 here, running 5.14.3.0.1. Jailbroken about a year ago, OTAs prevented and almost permanently in airplane mode.

Everything was working fine and exactly as expected. Yesterday, my KOA2 hung itself up and I rebooted. During the boot, "setup cover mode" (or similar) was displayed, indicating the jailbreak and tools are working fine.

After the reboot, my Kindle claimed the library was empty. KUAL wasn't displayed. The filesystem, though, is fine, all the files are there.

Originally installed after jailbreaking were these packages:

JailBreak-1.16.N-FW-5.x-hotfix.zip
kual-dyn-submenu-example-0.1.N.zip
kual-kual-plus-0.2.N-r13380.tar.xz
kual-helper-0.5.N-r18869.tar.xz
kual-gawk-1.5.N-r18869.tar.xz
KUAL-v2.7.26-g32b2e39-20220213.tar.xz
KUAL-e3deabf-20220213.tar.xz
kual-mrinstaller-1.7.N-r18896.tar.xz
kindle-usbnet-0.22.N-r18897.tar.xz
kindle-linkfonts-0.14.N-r18870.tar.xz
kindle-linkss-0.25.N-r18870.tar.xz
kindle-python-0.15.N-r18870.tar.xz
koreader-kindlepw2-v2022.05.1.zip

I reinstalled most of them in their current version (from the Snapshot thread) using ";log mrpi" which worked like a charm, further confirming the jailbreak is intact:

KUAL-ff4134d-20221017.tar.xz
KUAL-v2.7.29-g7750a3a-20221017.tar.xz
kual-mrinstaller-1.7.N-r18983.tar.xz
kual-gawk-1.5.N-r18977.tar.xz
kual-helper-0.5.N-r18980.tar.xz
KOL-0afc436-20220405.tar.xz
kindle-python-0.15.N-r18981.tar.xz
kindle-usbnet-0.22.N-r18981.tar.xz
kindle-linkfonts-0.14.N-r18981.tar.xz
kindle-linkss-0.25.N-r18981.tar.xz

I rebooted again and, to check for mere display issues, I copied an azw3 file onto the KOA2 and it was recognised.

Still, on-device only that one test document is shown in my library. No KUAL or anything else.

What else can I try?